Process of manufacturing powder of lead suboxide intermingled with power of metalliclead



Patented May 11, 1925.

UNITED STATES GENZO SHIMADZU, F KYOTO,. JAPAN.

PROCESS OF MANUFACTURING POWDER 0F LEAD SUBOXIDE INTERMINGLED WITH POWDER 0F METALLIC LEAD:

Io Drawing.

This application is a continuation in part of application Number 431,473, filed Dec. 17, 1920.

This invention relates to a process 01 5 manufacturing a very fine powder of lead suboxide intermingled with powder of metallic lead, consisting in putting pieces of metallic lead in a rotatable vessel, keeping the same at-a temperature not less than 60 (3., introducing into the vessel, while slowlyrotating, air or any gas containmg oxygen, or any other oxidizing agent, causing thus the surface of the pieces of metal lic lead to oxidize lead-suboxide, and reducing the suboxide thus formed into a very fine powder by abrasion. The object of this invention is to obtain a large quantity of a very fine chemically reactive powder the principal part of which is lead suboxide, by promoting reduction of the metallic lead pieces into powder by abrasion by converting the surface of the pieces to suboxide.

This invention consists in putting in a rotatable vessel pieces of metallic lead, keeping-these pieces at a temperature not less than 60 0.,and while rotating thevessel sending air, or'other gas containing oxygen thereinto, or sending any other oxidizing agent thereinto, thus oxidizing the surface of the pieces of lead and reducing them by abrasion into a very fine powder which is chemically very reactive.

In this invention the surface ofthe material, that is, metallic lead, is caused to be acted upon by the air or other oxidizing agent, and to be covered with a coating of lead-suboxide, which being brittle and lacking tenacitycompared with metallic lead, can be easily and quickly reduced into powder'by abrasion. And as soon as a new metallic surfaceof the pieces appears, it will be instantly oxidized and abraded, thus continuously producing the desired, powder- Thus, the efiiciency of manufacture is very great, and the product is a very fine oxidized powder of lead, which is chemically very reactive, intermingled only with a little coarsegrained powder.

The product of this invention is so fine that the apparent specific. gravity is 1-3. The composition of powder is approximately from 93 to 97% lead suboxide and about 3 to 7% metallic lead. It is a porous mass of amorphous particles and although not oxide resembles in its chemical and Application filed July 14, 1923. Serial No. 651,621.

very much different in its property irom metallic lead, it is so chemically reactive that it is spontaneously converted into pieces of lead convertedinto monoxide or litharge in a rotatable'drum, and excoriating the same. Another method known is to heat lead in a closed vessel to a point nearly approaching the. melting point in presence of. oxidizing agent and thus making lead oxide by heating. But these-have nothing to do with the manufacture of lead suboxide, and it is evident that the object of these processes is quite dilferent from that of the present invention, as'lead sub;

physical properties rather to metallic lead than to lead oxides; and I need not say that lead suboxide is quite different from other oxides of lead in brittleness, ductility & c., which are principal factors 1n reducing a substance into powder.

I will now give an example of putting my invention into practice.

Mount rotatably in a'horizontal position an iron cylinder about 60 inches long with a diameter of about 60 inches piercedall over with holes A; of an inch in diameter at a rate of four holes in one inch square, and put therein balls of metallic lead about one inch in diameter and also balls of steel or any other hard substance of about the same size. Provide the cylinder, or drum, With pipes to blow air thereinto. Now turn the cylinder at a rate of 25 times in one minute,

blowing air thereinto all the while, and

keeping the temperature within the cylinder at 60 to 200 G. Then the surface of lead balls will gradually be oxidized by the air, and they will be covered with a layer of lead suboxide, which is comparatively brittle and will be abraded into a fine powder. The

metallic surface of the lead balls exposed by the rubbing off of the layer of lead suboxide formed thereon, will be acted upon by air and being oxidized a layer of lead suboxide will be again formed which will be abraded off again as before. Thus, by oxican be very easily manufactured. The

dizing lead balls and abrading off the layer of lead suboxide thus formed, a fine powder der thus formed may be discharged ii'om the holes on the wall of the cylinder.

In this invention, as an oxidizing agent,

oxygen, hydrogen peroxide, ozone or a gas containing any of them, or anything that oxidizes the surface of metallic lead, may be utilized besides. air. Any such' oxidizing agent may be blown into the cylinder in a gust, or may cause the cylinder to suck it. If it is blown into, it is convenient to utillze the force of the current thus caused to blow the powder formed out of the cylinder, and then. collect it.

Again, inthis invention, in heating lead balls, frlotion heat or reaction heat caused by oxidationv of lead, or both may be utilized; or heat may be introduced from an electric heater, gas heater, or any other source. The main point is to maintain the material lead. in the atmosphere of air or any other oxidizing, gas at a temperatureof not less than 60 C. And in the case of utilizing friction or reaction heat that arises the its

while working this invention, itis preferable to provide around the rotating cylinder heat insulating a pliance to prevent the radiation thereof. so it goes without saying that production of heat'in this case may be regu ated by adjusting the weightof metallic balls, thus reducing or increasing friction: surface and pressure, or by increasing or reducing the number of rotations of the cylinder.

The advantages of this invention may be enumerated as follows (.1) It is easy to maintain the harmony of oxidation of the surface of the material lead, and abrasion, of oxidized lead; and a.

large amount of a fine powder of lead suboxide intermingled with powder of metallic lead, which does not practically difier in its to erties froma fine powder of metallic iha ,is obtained without using muchapowder.

(2) The rate of mixture of powder of metalli'c' lead and that of lead suboxide, the apparent specific gravity, and condition of particles, of the product may be altered by adjusting temperature, gust of oxidizing agent, &c.

Claims:

I. A process of manufacturing a fine powder of lead suboxide intermingled with powder of metallic lead, comprising in putting pieces of metallic lead in a rotatable vessel in a dry. state, introducing into the said vesselcurrents of an oxidizing gas to oxidize the surface of the. lead while rotating the said vessel, and abrading ofl the oxide formed on the surface.

, 2..- A process of manufacturing a fine powder of lead suboxlde intermingled with powder-of metallic lead, comprising in put- 4. A process of manufacturing a fine powder of lead suboxide intermingled with powder of metallic lead, comprising in puttin lead in a dry state, and rotatin the vessel maintaining the temperature wit in the vessel at not less than 60 C'., at the same time introducing into the vessel an oxidizing gas.

5. A process of manufacturing a 'fine powder of lead suboxide intermingled with powder of metallic lead, comprising in providing a rotatable vessel with a heat insulatin means, puttin in the vessel pieces of meta lic lead in a the vessel maintaining the temperature the lead at 6'0-- 20'0 C. and introducing into the vessel an oxidizing gas.

6. A process oi manufacturing a fine powder of lead suboxide intermingled with powder of metallic lead, comprisin in putting 1 n a rotatable vessel pieces 0 metallic lea introducing an therei'nto androtat'in the vessel maintainingthe temperature 0- the material at not. less than 60 C. by the heat generated by friction and-chemical reaction.

7. A process of manufacturing a fine powder of lead suhoxide intermingled with powder of metallic lead, comprisin in putting m a rotatable vessel ieces o metallic lea and balls of steel, an rotati the vessel maintaining the temperature 0 'the .con-' tents of the vessel at not less than 60 CL, at the same time introducing air into the vesry. state, and rotating in a rotatable vessel pieces of metallic sel, thus causing, oxidation and abrasion to the step of tumbling together and: agitating,

a mass of hard heavy material-containing" metallic lead, while maintained at a. temperatlre between about 60 Cl and about 200 I 9. A method. of forming. a finely divided powder containing a large proportion of 015- dized lead which comprises impinging, 9.- current of air on lead masses in a dry state, abrading the lead masses, and? controlling the temperature to obtain a; finely divide powder containingga large proportion. of oxidized lead;

10. A method of forming a finely divided powder containing alarge proportion ofoxidized lead which comprises impinging acurrent of air on lead masses in a dry state, and controlling the temperature to maintain the temperature above 60'degrees C. to obtain a finely divided powder, containing a large proportion of oxidized lead.

11. A method of forming a powder containing a large proportion of oxidized lead which comprises impinging a currentof air on lead masses in a dry state, abrading the lead masses, and controllin the current of air to obtain a finely divided powder, containing a large proportion of oxidized lead.

12. A method of forming a finely divided powder containing a large proportion of oxidized lead comprising impinging a current of air on lead masses in a dry state, abrading the lead masses, and controlling the temperature and current of airto obtain a finely dividedpowder containing a large proportion of oxidized lead.

13. A method of forming a finely divided powder containing a large proportion'of oxi-' dized lead which comprises impinging a curfinely divided perature to maintain the temperature above,

60 degrees C. to obtain a finely divided powder containing a large proportion of 0X1- dized lead.

14. Comminuted lead-lead suboxide mix--' ture with apparent specific gravity 1 to 3.

15. As a-new' composition of matter, a highly chemically reactive finely divided powder comprising a major portion of lead taneous oxidation. 1

16.As a new composition of matter, a

suboxide, said powder being capable of sponhighly chemically reactive powder, comprising a large portion of lead suboxide, said 1 powder being capable of spontaneous reaction on contact with moisture;

17. As a new composition of matter, a highly chemically reactive powder, comprising alarge portion of lead suboxide, said powder being capable of spontaneous reaction on contact with air. v

Intestimony whereof I have afiixed my signature.

GENZO SHIMADZU. 

